Carpet trimming tool



Jan. 16, 1968 G. A. O'BRIEN 3,363,314

CARPET TRIMMING TOOL Filed Oct. 2l, 1966 5 Sheets-Sheet l I j/ U' y T" llllllllmiif-zf@ i JZ Y Mam/m@ am@ ,4. awe/w Jan. 16, 1968 G. A. OBRIEN CARPET THIMMING TOOL 3 Sheets-Sheet 2 Filed Oct. 2l. 1966 1 N ff. Y? Kfm www W f A?, ZM Z JUL 16, 1968 G. A.OBR|EN l K 3,363,314

CARPET TR IMM ING TOOL Filed oct. 21. 1966 5 sheets-sheet s United States Patent O 3,363,314 CARPET TRIMMING TOL George A. GBrien, Chicago, Iii., assignor to Kinkead Industries Incorporated, Chicago, Ill., a corporation of Iliinois Filed st. 21, 1966, Ser. No. 588,439 12 Claims. (Cl. 30--125) The present invention relates to carpet installation tools and more particularly to a trimmer for trimming the edge of a piece of laid carpet to fit adjacent a wall or base board.

-It is an object of the present invention to provide a trimming tool which is highly effective and easy to use and which overcomes the disadvantages of conventional carpet trimmers, particularly those employing superimposed or stacked plate structures. It is a more specific object to provide a carpet trimmer which requires a minimum of adjustment to accommodate the various conditions of carpet thickness and the like which may be encountered by the installer and in which the adjustment of blade height, in positive finite steps, is easily and quickly accomplished simply by loosening and re-tighten- 'ing a single convenient knob without disassembling the unit.

It is another object of the present invention to provide a carpet trimmer having a minimum number of parts including a frame and blade subassembly, with novel means for holding the subassembly together before it is installed in the frame. The subassembly, in turn, consists of only two parts with means for locking the blade elements securely between them. In this connection it is an object to provide a carpet trimmer in which the blades may be easily and quickly replaced when renewal becomes necessary without risk and without need to eX- ercise any care or judgment. It is a more detailed object in this connection to provide a novel bayonet type connection capable of holding together the blade subassembly upon light ngertip manipulation and in which all parts of the subassembly and frame are iinally and securely clamped together by a single knob.

It is yet another object of the present invention to provide a carpet trimmer which is fast feeding, requiring a minimum of force to propel it along even when cutting carpeting having a heavy pile or backing. In this connection it is an object to provide a carpet trimmer in which a smoothly walled trough or groove is provided for the severed edge and in which there is no possibility of snagging the raw edge of the carpet.

It is still another object of the invention to provide a carpet trimming tool having a single mounting or base plate which presses against the carpet and which is free of any stacked or superimposed plates or the like so that the space surrounding the handle of the device is free and open to provide easy access to the clamping knob and permitting a comfortable grip.

It is one of the more detailed objects of the present invention to provide, adjacent the base plate and recessed under the handle, a novel accessible cache of replacement blades with means for holding the blades captive until intentionally removed.

Other objects and advantages of the invention will become apparent upon reading the attached detailed description and upon reference to the drawings of which:

FIG. 1 is a general perspective view of a carpet trimming tool constructed in accordance with the invention;

FIG. 2 is a top view of the device of FIG. 1;

FIG. 3 is an exploded view with portions broken away;

FIG. 4 is a vertical section taken along the line 4 4 in FIG. 2;

FIG. 5 is a somewhat similar section but taken along the line 5 5 in FIG. 2;

FIG. 6 is a fragmentary transverse section taken along the line 6 6 in FIG. 2;

FIG. 7 is a fragmentary perspective View of the tool showing the blade subassembly ready to be inserted into position.

While the invention has been described in connection with a preferred embodiment, it will be understood by those skilled in the art that the invention is not limited to the embodiment shown and that we intend to cover the various alternative and equivalent constructions lincluded within the spirit and scope of the appended claims.

Turning now to the drawings, the trimming tool includes a dat base plate 16 in the form of a generally rectangular plate of metal having turned up ends as indicated at 11, 12 for riding upon the nap or pile of a carpet. Along one edge of the device means are provided for mounting horizontal, angled cutting blades 15, 16 having edges i7, 18 which face outwardly in opposite directions and which lie adjacent a vertically arranged guide member 19. A handle 2t?, which is secured to the base plate by means of screws 21, 22 is in the shape of an arch, symmetrically formed to enable the trimmer to be pushed in opposite directions at the will of the user.

Referring to FIG. 6, which shows the intended mode of use, the carpeting 25 is anchored to a tack strip 26 to provide an upwardly turned edge 27 which is trimmed by one of the cutter blades as the device is pushed parallel to the wall, with the guide member 19 riding in contact with the wall for gauging purposes. After trimming, the trimmed edge 28 of the carpet is tucked into the space 29 behind the tack strip 26, using the curved ends of the guide 19 to do the tucking.

In accordance with the present invention a vertical wall is formed along one edge of the base plate and a trough member is provided having a bottom wall and a side wall, with means for mounting the cutter blades in oppositely facing positions on the bottom wall and with means for clamping the side wall to the vertical wall on the base plate. More specifically in accordance with the invention, a blade clamping member is employed as part of the combination having horizontal and vertical legs conforming to the bottom and side walls of the trough member, with the horizontal leg serving to hold the blades in place. The vertical leg is interposed between the adjacent walls and clamped securely between them when the clamping means is tightened. Thus, re-

ferring to the drawings, a vertical wall 30 is provided at the edge of the base plate 10. As an alternative to simply bending up the edge ofthe base plate, the wall 36 is formed as a separate piece having feet 31-34 which are spot welded to the base plate. As will be discussed the wall Sii has end portions 35, 36 and a central or mounting portion 37. Arranged adjacent the vertical wall 30 is a trough member 4t) having a side wall 41, a bottom wall 42 and an outer wall 43. The bottom wall 42 has oppositely facing supporting edges 45, 46 at the blade positions. The outer wall 43 serves as a convenient mount for the guide 19 which is spot welded to it. It will be apparent from FIG. 6 that the trough member defines a trough or groove 47 which serves to guide the severed edge of the carpet as it is cut by the cutting blade.

For the purpose of holding the blades in place a clamping member Si? is provided of L cross-section which conforms to the trough member 4i), having a lower leg 51 which engages the blades from the underside and a vertical leg 52 which is sandwiched between the walls 30, 41 when the device is clamped together. The ends of the horizontal leg 51 are relieved as indicated at 55, 56, and, preferably, the ends 45, 46 and 55, 56 which embrace the blades are notched in prole and ground to a shallow chamfer so as not to snag on the carpet as it is being cut. i

To lock the cutter blades in position, the trough member is preferably provided with downwardly struck projections, Vor locating pins, 61, 62 which register with holes 63 formed in the individual blades. Opposite the projections the horizontal leg 51 of the clamping member is notched or relieved as indicated at 65, 66. To support and protect the pointed tips of the blades the guide member 19 is preferably formed with struck-out tabs 67, 68, the upper edges of which provide supporting ledges for the tips (FIG. 3).

In accordance with one of the aspects of the present invention, means are provided for temporarily clamping or holding together the clamping member 50 and the trough member 40, with the cutter blades in position between them, as a subassembly, prior to final assembly with the vertical Wall on the base plate. For the purpose of registering the two members, the trough member is formed with a pair of struck-out tabs 71, 72 which register with window openings 73, 74 in the vertical leg of the clamping member, the openings being the spacesV vacated by further struck-out tabs 75, 76. The members are held together, in the present instance, by means of a clamping screw 80 which is captive in the wall 41 and which projects through a clearance opening 81 in the vertical leg of the clamping member. The temporary clamping effect is obtained by a bayonet pin 82 which is transversely mounted in the screw and which is rotatable into and out of register with a bayonet slot 33. Conveniently, the screw has a knurled portion 84 adjacent the bayonet pin and a spring washer 85, of the wavy type, under the screw head. Thus to put together the subassembly the clamping member 50 is seated upon the trough member 40, with the blades in place, following which the clamping screw S is rotated by the knurl 84 to turn the bayonet pin 82 around into horizontal interfering position in which the pin engages the lands on the opposite sides of the clearance opening 81. The spring washer 85 takes up any slack. The resulting subassembly may be handled as 'a unit conveniently and safely, with the cutter blades in protected position, prior to the nal clamping onto the wall 30 of tl e base plate (see FIG. 7).

To complete assembly with t'le base plate, wall 30 of the base plate is formed with a central clearance opening 91 which receives the shank of the screw 80, the presented end of the screw being engaged by an internally threaded clamping knob, or nut, 92. The knob 92 is large enough to be easily grasped and has a wide base 93 for engaging the back side of the wall 30. On each side of the central clearance opening 91 are windows v95, 96 which register with, and provide clearance for,

the struck-out tabs 75, 76 on the clamping member.

In carrying out the present invention, novel means are provided for varying the effective height of the blades with respect to the base plate while, at the same time, insuring that there will be no relative cocking movement of the clamped members with respect to one another. Thus we provide, at the ends of the vertical leg 52 of the clamping member, pin projections 101, 102 which engage registering openings 103, 104 in the wall of the base plate. To enable selection of relative height, the registering openings 103, 104 are provided with enlargements as indicated at 10351, 103b, and 103C. The a, b and c positions, by providing successively greater cutting heights for the cutter blades, determine the width of the tucked border portion of the carpet.

In order to insure that corresponding positions in the apertures 103, 104 are engaged by the projections 101, 102, and to recess the edges of the trough member and clamping members so that they do not catch upon the the vertical carpet passing through the trimmer, the central portion 37 of the wall 30 is preferably recessed with respect to the end portions 35, 36. In short, the vertical wall in the base plate is formed to provide a box-shaped receptacle which is of suliicient depth so that the front face of the wall 41, which is engaged by the pile of the carpet during the severing operation is ush with, and forms a continuation of, the end surfaces 35, 36 on the wall of the base plate.

In assembling the trimmer as, for example, incident to changing blades, the trough member 40 is inverted and the blades 15, 16 are registered on the bladelocating .pins 61, 62. The blade clamping member 50 is then slipped over the trough member into its blade-retaining position, with the clamping screw extending through the clearance opening 81 and with the tabs 71, 72 seated in the openings 73, 74. The knurl 84 is then twisted with the fingers to turn the bayonet pin 82 crosswise in the opening S1 which completes the blade subassembly. The subassembly is then inserted into the wall of the base plate with the pin projections 101, 102 at a desired height in the heightadjusting openings 103, 104 `and with the tabs 75, 76 registering with the windows 95, 96. For the purpose of providing clearance for, and locking, the bayonet pin 82, the clearance opening 91 is formed with registering notches 105, one for each of the three positions of height adjustment. Assembly is completed by screwing on the threaded knob 92 which is turned tight to firmly clamp all of the wall members together into a rigid unit.

When it is `desired to change the height adjustment, it suices to unscrew the clamping knob 92 a few turns, enough to back the pins 101, 102 out of the openings 103, 104. Following this the blade subassembly maybe moved a short distance upwardly or downwardly as required, bringing the projections 101, 102 into a new registering position and following which the knob 92 may be retigbtened.

Experience has shown that the present trimmer is unusually convenient to operate, cutting the carpeting without regard to the thickness of the pile or backing cleanly and etortlessly with minimum necessity for adjustment. During use the guide member 19 rides along the wall but it is so dimensioned that it does not extend so low as to engage the floor. As a result of mounting the blade subassembly outboard on an outer vertical wall of the base plate, the space above the base plate, indicated at in FIG. 6, is maintained free, open and uncluttered by any stacked or superimposed structure. This provides clearance space for the hand of the user enabling him to grasp the handle 20 lfrom any direction without interference. Moreover the ample arched nature of the handle provides a large central opening for access to the clamping knob 92, permitting the same to be turned as tight as desired. In addition, blade storage under the handle of the trimmer. p

Thus, in accordance with one of the more detailed aspects of the invention, we provide a blade containing tray which is in the form of a flat piece of plastic pivoted to the base plate at 121 and normally occupying a cut-out space 122 under the Ycentral portion of the handle 20. 'Ihe tray 120 has a central opening 123 formed therein of a diamond shape generally conforming to the shape of the blades with supporting ledges vand an integral overlap or keeper 124. The latter is hinged about its mounting edge and may be readily bent up to free the blades. In order to expose the tray, the tray is formed with a lateral extension 125 which projects into the free space 110 as well as a serrated outer edge 126.V Thus when a new blade is required, ngertip pressure is rapplied to the extension 125 pushing the tray outwardly to the point where the serrated edge 126 can be engaged to swing the tray out to the exposed position shown dotdash in FIG. 2. The blade is removed following which the tray may be pressed back into its recessed position.

the central space 110 facilitates Y In the following claims the term trough member vapplies to the member 40 having opposed side walls and a bottom wall forming a groove or trough for the trimmed edge of the carpet. However it will be understood that We do not intend to limit the interpretation of this term to the particular and preferred configuration shown in the drawings but intend to cover any member having at least one horizontal bottom wall for mounting the blades in the position shown and a side wall for the purpose of securing the member to the vertical wall of the base plate. It will be apparent to one skilled in the art that such side wall may extend upwardly from the blade level, as shown, or downwardly, or indeed in both directions, without departing from the invention. The wall 43 is optional. The term dat base plate shall be understood to mean any base member having a surface capable of support upon the nap or pile of a carpet to serve as the plane of reference for the cutter blades.

I claim as my invention:

1. In a carpet trimmer the combination comprising a at base plate having a vertical wall extending along one edge and an upstanding handle extending along the opposite edge, a blade-holding trough member having a bottom and side wall having provision for mounting cutter blades in oppositely facing positions at the bottom edges thereof, a cutter blade securing member having a lower leg which underlies the blades to hold them in position and a vertical leg, and means for clamping the side wall of the trough member to the vertical wall of the base plate with the vertical leg of the blade-securing member sandwiched between them.

2. In a carpet trimmer the combination comprising a dat base plate having a vertical wall along one edge and an upstanding handle at the opposite edge, a blade-holding trough member having a bottom and side wall, means for mounting cutter blades in oppositely facing positions at the bottom edges of the trough member, and means for clamping the side wall of the trough member to the vertical wall of the base plate.

3. In a carpet trimmer the combination comprising a flat base plate having a vertical wall along one edge and an upstanding handle spaced from the wall to define a clear and open space inbetween, a blade-holding trough member having a bottom and side wall, means for mounting cutter blades in oppositely facing positions at the bottom edges of the trough member, and clamping means for clamping the two walls together including a screw extending through said walls and a threaded clamping knob in said space.

4. In a carpet trimmer the combination comprising a at base plate having a vertical wall along one edge and an upstanding handle spaced from the wall to dene a clear and open Space in between, a blade-holding trough member having a bottom and side wall, means for mounting cutter blades in oppositely facing positions at the bottom edges of the trough member, and clamping means for clamping the two walls together including a single centrally-located screw extending through said walls and a threaded clamping knob in said space, the handle being of arch shape and having a large central opening for providing access to said knob.

5. In a carpet trimmer the combination comprising a llat base plate having a vertical wall along one edge and an upstanding handle, a blade-carrying trough member having a bottom and a side wall, means for mounting cutter blades in oppositely facing directions at the bottom edges of the trough member, the vertical wall on the base plate having a shallow box-like recess formed therein for registered substantially flush nesting of the side wall of the trough member for free ow of the severed edge of the carpet cut by one of the blades.

6. In a carpet trimmer the combination comprising a flat base plate having a vertical wall along one edge and an upstanding handle, a blade-holding trough member having a bottom and a side wall, means for mounting a cutter blade in horizontal position at at least one of the bottom edges of the trough member, and means for clamping the side wall of the trough member to the vertical wall of the base member at a plurality of selectable vertical positions thereby to vary the height of the blade relative to the base plate and the width of the trimmed edge of the carpet.

7. In a carpet trimmer the combination comprising a llat base plate having a vertical wall along one edge and having an upstanding handle extending along the other edge, a blade-holding trough member having a bottom and side wall, means for mounting oppositely facing cutter blades at the bottom edges of the trough member, one of said walls having laterally extending projections at its ends and the other of said walls having selectively engageable registering openings spaced at different levels to vary the elevation of the trough member and hence the elevation of the blades with respect to the base plate, and means including a central clamping screw for seating the projections in the selected openings and for clamping the walls rigidly together.

8. In a carpet trimmer the combination comprising a ilat base plate having a vertical wall extending along one edge and having an upstanding handle extending along the opposite edge, a trough member having a bottom wall and opposed side walls, a blade-securing member having horizontal yvertical portions cooperating with the bottom and one side wall of the trough member, oppositely facing cutter blades interposed between the trough member and the blade-clamping member, means for holding the trough member and blade-securing member together to form a unit subassembly with the blades installed, and means for attaching the subsassembly to the vertical wall of the base member. O

9. In a carpet trimmer the combination comprising a at base plate having a vertical wall extending along one edge and having an upstanding handle extending along the opposite edge, a trough member having a bottom and side wall, a blade-securing member of L cross section having horizontal and vertical legs conforming to the bottom and side walls of the trough member, oppositely facing cutter blades interposed between the trough member and the blade-securing member, means for holding the trough member and blade-securing member together, for handling as a unit subassembly with the blades installed, and threaded means including a clamping knob for clamping the subassembly atly to the vertical wall of the base member.

10. In a carpet trimmer the combination comprising a at base plate having a vertical wall extending along one edge and having an upstanding handle extending along the opposite edge, a trough mem-ber having a bottom and side wall with provision for mounting cutter blades in oppositely facing positions below the trough member at lthe ends thereof, a conformingly shaped blade clamping member having a horizontal leg underlying the blades for holding them in position and a vertical leg which lies flatly against the side wall of the trough member, a clamping screw extending through the side wall of the trough member and the vertical leg of the clamping member shaped to provide a bayonet connection to maintain the trough member and clamping member assembled together with the blades between them as a subassembly, the vertical wall of the base member having an opening for receiving the clamping screw, and a threaded knob for engaging the end of the clamping screw for clamping the subassembly to the vertical wall of the base plate.

11. In a carpet trimmer the combination comprising a flat base plate having a Vertical wall extending along one edge and having an upstanding handle extending along the opposite edge, a trough member having a bottom and side wall with provision for mounting oppositely facing cutter blades at the lower edges thereof, a clamping member having horizontal and vertical legs for conforming to the trough member to hold the blades in cutting position, a lclamping screw loosely mounted in the wall of the trough member and having a bayonet pin therein, a registering bayonet opening in the clamping member vfor receiving the screw and for holding the two members assembled together to form a subassembly, the vertical wall on the base plate having an opening for receiving the screw, and a threaded knob positioned between the vertical wall and the handle for screwing tightly to said screw to clamp the subassem-bly rigidly to the wall of the base plate.

12. In -a carpet trimmer, the combination comprising ya ilat base plate having a vertical Wall extending along one edge and having an upstanding handle extending along the opposite edge, means for detachably supporting a knife blade projecting horizontally from the wall for trimming of an upturned edge of a carpet, said handle being relieved along its under-side to provide a fiat elongated space between the handle and the Ibase plate, a flat tray dimensioned to t in said space land having a central receptacle -for storing replacement blades, said tray being pivoted #at one end for horizontal swinging movement between a closed position in which the tray is recessed in said space with the blades held captive therein and an open position in which the blades are accessible for removal, and means at the edge of the tray for digital engagement when the tray is in closed position for starting movement thereof to the open position.

References Cited UNITED STATES PATENTS 1,759,051 5/ 1930 Henderson 206--38 2,607,115 8/ 1952 Iovinelli 30-293 2,772,474 12/ 1956 Hill et al 30-293 JAMES L. JONES, JR., Prmaxry Examiner. 

12. IN A CARPET TRIMMER, THE COMBINATION COMPRISING A FLAT BASE PLATE HAVING A VERTICAL WALL EXTENDING ALONG ONE EDGE AND HAVING AN UPSTANDING HANDLE EXTENDING ALONG THE OPPOSITE EDGE, MEANS FOR DETACHABLY SUPPORTING A KNIFE BLADE PROJECTING HORIZONTALLY FROM THE WALL FOR TRIMMING OF AN UPTURNED EDGE OF A CARPET, SAID HANDLE BEING RELIEVED ALONG ITS UNDER-SIDE TO PROVIDE A FLAT ELONGATED SPACE BETWEEN THE HANDLE AND THE BASE PLATE, A FLAT TRAY DIMENSIONED TO FIT IN SAID SPACE AND HAVING A CENTRAL RECEPTACLE FOR STORING REPLACEMENT BLADES, SAID TRAY BEING PIVOTED AT ONE END FOR HORIZONTAL SWINGING MOVEMENT BETWEEN A CLOSED POSITION IN WHICH THE TRAY IS RECESSED IN SAID SPACE WITH THE BLADES HELD CAPTIVE THEREIN AND AN OPEN POSITION IN WHICH THE BLADES ARE ACCESSIBLE FOR REMOVAL, AND MEANS AT THE EDGE OF THE TRAY FOR DIGITAL ENGAGEMENT WHEN THE TRAY IS IN CLOSED POSITION FOR STARTING MOVEMENT THEREOF TO THE OPEN POSITION. 